The present invention relates to the dressing of grinding wheels in order to impart a desired profile to the circumferential edge thereof.
For many industrial purposes, there is a need for grinding wheels whose circumferential surfaces are formed to have relatively complex, dimensionally precise profiles. For example, if a grinding wheel is to be employed to grind turbine root serration cutters, a grinding wheel profile composed of a plurality of precisely dimensioned recesses and lands must be created.
It is known to dress such grinding wheels, i.e., to create the desired profile on the grinding wheel circumference, by the use of a numerically controlled grinder which advances a diamond nib along a path corresponding to the desired profile. The nib is caused to execute a large number of passes parallel to the axis of rotation of the grinding wheel while tracing the desired profile as the grinding wheel is rotated about its axis. As the profile is being formed in the outer surface of the grinding wheel, the nib is fed progressively in the radial direction toward the grinding wheel axis. The diamond nib may be in the form of a cylinder whose axis lies in a plane perpendicular to the axis of rotation of the grinding wheel.
It has been found that when this procedure is employed for grinding profiles having certain geometries, inaccuracies occur in the profile being formed and applicants have discovered that this was due to uneven wear experienced by the diamond nib, resulting in the development of a flat spot on one side or the other, accompanied by development of a sharp corner along the portion of the diamond which faces the grinding wheel axis of rotation. This problem appeared to be particularly pronounced when one side of each recess of the grinding wheel profile formed a large angle with the grinding wheel axis of rotation.